The impact intentional weight loss can have on patients living with sleep apnea

Abstract

Background: As the global prevalence of obesity continues to rise, the health and economic burden of a variety of obesity-related complications is becoming more substantial. A body mass index (BMI) over 25 kg/m2 is considered overweight, and over 30 kg/m2 is used to define obesity. Obesity is a recognized risk factor for many illnesses, such as type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), hypertension, myocardial infarction, and vascular disease, osteoarthritis, multiple cancers, and obstructive sleep apnea (OSA). the development of Obstructive Sleep Apnea (OSA), a widely underdiagnosed condition which impacts significantly patient health and quality of life. In recent years, devices that enable diagnosis and monitoring of OSA in the community have become more popular, given the extensive resource requirements of formal full polysomnography (PSG) testing for OSA. Objective: The first study aimed to determine changes in detailed polysomnography parameters after weight loss surgery in patients with obstructive sleep apnea. The second study aimed to investigated whether liraglutide 3.0 mg would reduce the severity of OSA and other obesity-related complications compared with usual care. The third study aimed to assess the result of bariatric surgery on OSA and other obesity-related complications. Methods: The first study, recruited 5 patients in the Sleep Disorders Unit in St Vincent‟s Healthcare Group, Dublin Ireland, between 2019 and 2021. The second study recruited 40 patients from the STRIVE study at St. Vincent’s University Hospital (SVUH), Dublin, between 2019 and 2020 and the third study recruited 24 patients from the bariatric surgery unit at St. Vincent's University Hospital (SVUH), Dublin, from 2018 to 2020 with a BMI of 38.4 to 58.2 kg/m2, before and after laparoscopic sleeve gastrectomy (LSG) or Roux- en-Y gastric bypass (RYGB). In the first study, the 5 patients completed a questionnaire concerning possible daily or nocturnal symptoms, medication, intoxications, and medical history. The Epworth Sleepiness Scale (ESS) was included in the questionnaire. Patients used a scale of 0–3 for each of the questions on the ESS. The scale measured the level of falling asleep in eight different situations, giving an overall score between 0 and 24: the higher the 5 score, the sleepier the individual. We performed overnight polysomnography (PSG) on all 5 patients. PSGs were conducted preoperatively and postoperatively within one year. Embla Sandman, Version 10.1.1, was used to conduct PSGs. For the second and third study the King's Obesity Staging Criteria (KOSC) was used. The KOSC comprise nine health domains: Airways, Body mass index, Cardiovascular disease, Diabetes, Economic complications, Functional limitations, Gonadal axis, Health status (perceived), and Body Image. These domains were used to assess the effectiveness of Liraglutide 3.0mg for weight-loss (in the second study) and bariatric surgery for weight loss (in the third study). Results: In the first study on 5 patients, the following parameters were tested 1) apnea, 2) oxygenation, 3) symptoms of sleepiness, 4) sleep and 5) surrogate markers of cardiovascular risk after one-year bariatric surgery. We observed a significant improvement in the majority of polysomnography parameters. The severity classifications Apnea Hypopnea Index (AHI) used were mild (AHI = 5-14), moderate (AHI = 15- 30), and severe (AHI > 30). We found that participants' total AHI had improved significantly in Hypopnea (p < 0.03) and Apnea Hypopnea Index (p < 0.03). In the second study on 40 patients and the third study on 24 patients, the King's Obesity Staging Criteria (KOSC) comprise nine health domains: each domain, a person's health is assigned a score of 0 ('normal health'), 1 ('at risk'), 2('established disease'), or 3 ('advanced disease'). The two groups were analyzed using multivariate logistic regression to evaluate the null hypothesis that there is no change in participants' 9 domains between the two groups when measured at baseline and 52 weeks after commencement as part of the STRIVE RCT. Multivariate logistic regression showed a trend towards those without OSA benefiting more in cardiovascular health (p = 0.06). Those with OSA benefited more regarding improved in body image after 52 weeks (p =0.03). Conclusion: The three most important findings and the meaning of our study were improvements in the patient's OSA as measured by AHI. The study also demonstrates statistically significant correlations between AHI and anthropometric variables of weight, BMI, waist circumference, and neck circumference while suggesting baseline AHI may have been used as a predictor for AHI improvement with weight-loss 6 interventions. All oxygen parameters improved significantly after bariatric surgery and decreased the risk of coronary artery disease, heart attacks, heart failure, and strokes.